Fuel injector manifold and mounting arrangement

ABSTRACT

A liquid injector manifold and mounting arrangement wherein the fuel injector is supported in the engine at one end in a cylindrical bore with the aid of a circular seal. The injector extends from the engine and is supported at its other end by an extending fitting which tees off from a tubular common rail liquid fuel manifold. The tubular liquid fuel manifold is supported by brackets at a raised elevation. The connection between manifold fitting and fuel injector also employs a cylindrical surface and circular seal connection.

Unlted States Patent 1 1 1111 3,776,209

Wertheimer et al. Dec. 4, 1973 a [54] FUEL INJECTOR MANIFOLD AND3,605,703 9/1971 Moulosml 123/32 AE MOUNTING ARRANGEMENT 1,361,28812/1970 Pyle 123/148 A [75] Inventors: Harry P. Wertheimer, Horseheads;

William A. Peterson, Jr Coming FOREIGN PATENTS OR APPLICATIONS both OfN.Y. 492,585 5/1953 Canada 239/550 [73] Assignee: The BendixCorporation, Southfield,

Primary ExaminerWendell E. Burns [22] Filed: Apr. 5, 1973Attorney-William S. Thompson [21] Appl. No.: 348,360

Related US. Application Data [63] Continuation of Ser. No. 181,680,Sept. 20, 1971, [57] ABSTRACT abandoned.

A liquid injector manifold and mounting arrangement [52] US. Cl. 123/119R, 123/32 R, 123/52 M, wherein the fuel injector is supported in theengine at 123/ 139 AW, 239/550 one end in a cylindrical bore with theaid of a circular [51] Int. Cl. F02m 55/00 seal. The injector extendsfrom the engine and is sup- [58] Field of Search 123/32 AB, 32 EA,ported at its other end by an extending fitting which 123/148 A, 32 V,139 AW, 32 E, 119 R, 32 tees off from a tubular common rail liquid fuelmani- SU, 32 F, 32 G, 32 H, 32 R, 52 M; 285/345; fold. The tubularliquid fuel manifold is supported by 239/550, 551 brackets at a raisedelevation. The connection between manifold fitting and fuel injectoralso employs a [56] References Cited cylindrical surface and circularseal connection.

UNITED STATES PATENTS 3,412,718 11/1968 Long 123/32 AB 1 Claim, 5Drawing Figures MENTEU DEC 4 I975 SHEET 15? 2 HARRY P. WERTHEIMERWILLIAM A PETERSON, JR.

INVENTORS PATENTEDDEB 4 ms 3, 776. 209

HARRY F? WERTHEI MER WILLIAM A. PETERSON, JR.

INVENTORS FUEL INJECTOR MANIFOLD AND MOUNTING ARRANGEMENT This is acontinuation, division, of application Ser. NO. 181,680, filed Sept. 20,1971 now abandoned.

BACKGROUND OF THE INVENTION Liquid fuel injection systems are receivingincreasing acceptance because of the need for more accurate fuelhandling systems to combat excessive exhaust emissions. Unfortunately,fuel. injection systems are complex andexpensive, particularly multiplepoint injection systems where injection occurs adjacent each enginecylinder or subgrouping of cylinders. Another problem has been todissipate heat in and around the injectors to reduce consequent fuelvaporization which leads to loss of metering accuracy.

DESCRIPTION OF THE PRIOR ART Perhaps the most common prior art approachto injector mounting is to simply form a boss on the engine block or airintake manifold for each injector-location, drill and thread the boss,and form complementary threads on the injector housing. Thus, theinjector is securely mounted and entirely supported at one end, asillustrated in prior U. S. Pat. No. 2,980,090. The injector may bepartly recessed and arranged to receive fuel from passages partly formedin the block as illustrated in U. S. Pat. No. 3,247,833. Inpriorpractice, the liquid fuel manifold does not substantially assist insupporting the injectors;

SUMMARY OF THE INVENTION In the present invention the liquid fuelmanifold is utilized as a support member at one end of the injectorvalve, giving the required structural support without the necessity ofexpensive pockets or passages or thread-forming operations. Moreover, bythe use of circular seals on cylindrical surfaces at the connectionpoints at either end of the injector, mating tolerances along theinjector valve axis are considerably relaxed.

I BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of a commonfuel rail injector valve installation as it might appear for one bank ofa V-8 engine;

FIG. 2 is a side view of the installation of FIG. 1;

FIG. 3 is an end view of the installation of FIG. 1 showing particularlyin detail the support bracket for common injector fuel rail; and

FIGS. 4 and 5 illustrate two configurations of injector mounting detail.

DETAILED DESCRIPTION OF THE DRAWINGS The drawings illustrate a commonrail liquid fuel distribution injection system which is particularlyarranged to provide good support for the injectors by means of amounting technique which can be easily manufactured in mass productionwith very low tolerance requirements.

The common fuel rail or manifold consists of interconnected passages 10,12, and 14 which receive fuel through tee connection 11 from a fuelinlet 9. A fuel return passage 18 is normally provided, leading back tothe fuel tank (not shown) from fuel pressure control valve 16.

A portion of the engine in the embodiment of FIGS. 1-3 is designated bynumeral 20 which is representative of that portion of the engine whereit is desired to mount the injectors. This may be either the engineblock per se, cylinder head(s), or a portion of the air intake manifold,depending on engine and manifold design and desired point of injection.A pair of wingshaped brackets 22 and 24, best shown in FIG. 3, areaffixed by studs 26 to the top of engine portion 20 to provide rigidfixed support members for the fuel rail. Horseshoe straps 28 secure fuelrail passage 12 to the ends of the support brackets at a point of raisedelevation above the engine. A plurality of fittings 30a, 30b, I

300, and 30d are secured to fuel rail passage 12 at spaced locations andeach receives the top end of a respective injector 32a, 32b, 32c, and32d. The injectors may be of several well-known types ofelectromechanical injector valves, two configurations of which areillustrated in the referred to prior patents. The lower ends of theinjector valves are received in the raised bosses 34a, 34b, 34c. and 34dformed in the engine block or manifold 20. Each injector also has anelectrical connector 36a, 36b, 36c and 36d respectively to supply theenergizing electrical energy to selectively open the injectors atdesired intervals.

Referring to FIGS. 4 and 5, two configurations illustrating the injectorsupport connections are shown. In the FIG. 4 arrangement, the injector32a is received in cylindrical bore 40 formed in the engine portion 20which bore contains a seal groove 42 which receives elastic ordeformable circular seal 44. On its inner diameter seal 44 cooperateswith a large diameter cylindrical surface 46 formed on the injectorhousing which permits the injector to project well through the enginewall. The elastic seal on cylindrical surface permits tolerances to berelaxed inboth the radial and axial directions. The seal will, ofcourse, deform to compensate for radial deviations in dimensions orconcentricity and is capable of sealing along a considerable length ofcylindrical surface 46 of the injector to accept wide deviations in anaxial sense.

FIG. 5 shows most clearly the connection between I the other end of theinjector and fitting 30b. Fitting 30b is secured to fuel rail 12 bybrazing or the like. A hole 48 is drilled through the side wall of tube12 to permit fuel to flow into the cylindrical bore 50 formed in thefitting. A seal groove 52 receives an elastic and deformable circularseal 54. Seal 54 cooperates with the cylindrical surface 56 formed onthe injector end to accept both radial and axial tolerance variations inthe manner previously described and perform a liquid-to-air sealingfunction.

Referring to FIGS. 1 and 2, it will be noted that each fitting 30 is aspaced distance away from the points of connection of the fuel rail torigid supports 22 and 24. The fuel rail may be of simple metal tubularconstruction or equivalent materials and configuration to permit somedeflection or bending transversely to the axis of the fuel rail. Thus,the fitting may be utilized to provide an axial seating load to theinjector housing and may be displaced by bending the fuel rail to acceptfurther tolerance variations and facilitate injector assembly and/orreplacement. While an axial seating load has some locating advantages,it is not. essential to the practice of the invention since sealing atboth ends is accomplished by radial compression of the deformable ple,easy to machine, cylindrical surfaces are utilized at the attachmentpoints and elastic seals, which permits manufacturing tolerances to beconsiderably relaxed. The use of the fuel rail as an injector supportdevice utilizes existing structure to perform" an additional functionwith virtually no increase in cost, but merely by means of judiciousarrangement. The injectors are mounted to project well out of the engineblock and need not be recessed therein to provide good ventilation whilestill having durable two-point support.

I claim:

l. A fuel injector mounting arrangement for an engine comprising:

a tubular common fuel rail for maintaining an available standby sourceof fuel; a rigid bracket member connected to said fuel rail and adaptedto be fixedly attached to an engine to provide support at a locationalong the fuel rail;

at least one fitting connected to said fuel rail a spaced distance fromthe location of support provided by said bracket member; and

an injector valve assembly having connections at each end with saidfitting and the engine to provide two-point support at spaced distancesalong the length of the injector valve, each said end connections havingits respective interfitting cylindrical surfaces aligned along thelongitudinal axis of the injector valve assembly and each end connectionarranged to confine movement of the injector valve assembly in onedirection while permitting slidable movement in the opposite directionalong said axis.

1. A fuel injector mounting arrangement for an engine comprising: atubular common fuel rail for maintaining an available standby source offuel; a rigid bracket member connected to said fuel rail and adapted tobe fixedly attached to an engine to provide support at a location alongthe fuel rail; at least one fitting connected to said fuel rail a spaceddistance from the location of support provided by said bracket member;and an injector valve assembly having connections at each end with saidfitting and the engine to provide two-point support at spaced distancesalong the length of the injector valve, each said end connections havingits respective interfitting cylindrical surfaces aligned along thelongitudinal axis of the injector valve assembly and each end connectionarranged to confine movement of the injector valve assembly in onedirection while permitting slidable movement in the opposite directionalong said axis.